The only types of network-attached storage (NAS) supported by ESXi are those with NFS protocols, NFS 3, or NFS 4.1 (starting with vSphere 6.0), both over TCP (by default NFS is on the UDP transport protocol). Like software iSCSI, an ESXi host needs a proper VMkernel and virtual network configuration to access a remote NFS server.

Note that there isn't a specific type of VMkernel interface for NFS traffic; depending on your routing table the right interface is chosen properly.

To add a new NFS datastore, proceed with the following steps:

1. Choose Add new datastore
2. Select NFS type
3. Choose the right protocol type as shown as follows:

4. Provide the storage information; that is, at least, a folder of the share (usually, is the full path), and the name or IP of the storage shown as follows:

For a NFS 4.1 datastore, you also have to provide Kerberos authentication if needed.

NFS 3 uses one single TCP connection between client and server. For this reason, ESXi does not support multiple paths and the only solution is to work with more IPs at storage side and use link aggregation. NFS 4.1 provides multipathing for servers that support the session trunking. When the trunking is available, you can use multiple IP addresses to access a single NFS volume. Client ID trunking is not supported. Storage vendors usually detail the required configuration to provide better scalability, the best resiliency, and also if some specific tuning could be requested.

The main differences between NFS 3 and 4.1 are summarized in the following table:

Virtual disks created on NFS datastores are thin provisioned by default. To have thick-provisioned VMDK as well, you must have VAAI compatible storage that supports the Reserve Space operation. VAAI will be discussed later.